JPS60202109A - Styrene copolymer - Google Patents

Abstract

PURPOSE:A styrene copolymer having a small and uniform particle diameter and capable of providing a product of excellent antistatic property, obtained by copolymerizing styrene with a styrenesulfonate and an alkyl methacrylate. CONSTITUTION:Styrene is emulsion-copolymerized with a styrene-sulfonate and an alkyl methacrylate in the presence of a redox initiator or a radical polymerization initiator to obtain a styrene copolymer comprising 3-90mol% structural units of formula I [wherein M is an alkali (alkaline earth) metal, or ammonia], 1-90mol% structural units of formula II and 1-60mol% structural units of formula III (wherein R is a 1-15C alkyl) and having an intrinsic viscosity >=0.05dl/ g and a MW of 2,000-1,000,000.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a styrenic copolymer capable of forming uniform fine particles. More details on styrene.

The present invention relates to a novel copolymer obtained from styrene sulfonate and l-methacrylic acid alkyl ester.

It has been known that a styrene sulfonic acid moiety/styrene copolymer has excellent antistatic properties and is useful as a latex for diagnostic reagents.

However, the conventionally obtained styrene sulfonate/styrene copolymer cannot be obtained as a latex with a microparticle size. However, it has drawbacks such as not being able to form a uniformly thin film, and not penetrating deep enough to impregnate and fix textiles and paper. Also 1
Latex for diagnostic reagents is particularly required to have emulsion particles with a uniform microparticle size, but it is difficult to obtain microparticles, and production facilities require extremely precisely controlled reaction equipment. Unless it is used, particles with a minute size cannot be obtained, which is extremely inconvenient for industrial production.

In view of the above circumstances, the present inventors conducted intensive research to obtain a styrene sponate/styrenic copolymer having small and uniform particle diameters, and as a result, they completed the present invention. I came to the conclusion.

That is, the present invention provides structural unit 3 represented by the following formula (I)
~90 moIv% + a molecular weight of 2000 to 1 consisting of 1 to 90 moA/% of the structural unit represented by the following formula CI[] and 1 to 60 moA/L/% of the structural unit represented by the following formula CI[]
Made of 1,000,000 styrene copolymer.

05M -CH2-CH- ■ CH Haruka In the present invention, M in the formula (I) is) IJum.

Indicates alkali metals such as potassium, alkaline earth metals such as calcium and magnesium, or ammonium. Note that when the copolymer of the present invention is used as an antistatic agent, 1M
is preferably an alkali metal.

In the above formula (I[), R is methyl, ethyl, or propyl.

Guchigami Amil, Heki V beggar 2-ethylhexyl.

Desir, Unde S/ /L/, Lauriku Tridesi/
It is an alkyl group having 1 to 15 carbon atoms, such as L/, tetrazoV, and pentadecyμ. The number of carbon atoms in the alkyl group is 1
If it exceeds 5, disadvantages such as a significant decrease in the monopolymerization rate during polymerization of the copolymer occur, which is not preferable.

The method for obtaining the copolymer of the present invention includes formulas CI) to (III)
), styrene sulfonate, styrene, and methacrylic acid alkyl ester are used as raw materials, and others such as benzoyl peroxide and azobisisobutyronitrile.

It can be obtained by any method such as emulsion polymerization method or suspension polymerization method together with a radical polymerization initiator or the like.

In the copolymer of the present invention, the styrene sulfonate unit represented by the formula CI) must be contained in an amount of 3 to 90-1:77%, more preferably 5 to 90-1:/L/%. If the content of styrene sulfonate units is less than 3 moA/%, sufficient antistatic properties will not be achieved.

On the other hand, if it exceeds 90 molts, it is not preferable because it gives a sticky feeling when processed into fibers or paper, and the antistatic property decreases with long-term use.

The styrene unit represented by the formula (II) is 1 mo/l/%
or more, 907 rou or less, more preferably 10 moA/%
As mentioned above, it is preferable that the content is within the range of 90%V% or less. If the content of styrene units is less than 1 mole, an emulsion with a minute particle size cannot be obtained, and 90 mole/L
If the amount of styrene exceeds 0.2%, the antistatic properties will deteriorate, which is not preferable.

The methacrylic acid alkyl ester unit represented by the formula (I[) is 17 moles or more and 60 moles or less, preferably 1 mole
It is preferably contained in an amount of mol or more and 507 ru or less.

If the methacrylic acid alkyl ester □ unit is less than 1 mole, an emulsion with a fine particle size cannot be obtained, and if the methacrylic acid alkyl ester is more than 60 motv%, the particle size will become large, which is not preferable. Furthermore, in fields such as fibers and paper which require even more uniform and finer particle diameters, it is preferable to use 50 molti or less.

In addition, each composition ratio of the copolymer of the present invention is shown in triangular coordinates in FIG. The copolymer of the present invention has a composition ratio shown in the range surrounded by ABCDEF, preferably A'B/C'
This is the range surrounded by D'F.

As described above, the copolymer of the present invention having such a structure has a molecular weight of 20
000,000 to 1,000,000, and an intrinsic viscosity of 0.05 dJ/f or more, preferably Q, ldJ/f or more. When the intrinsic viscosity is less than 0.05 d179, organic solvent resistance decreases when processed into fibers, etc.
This is not preferable because the antistatic properties may be lost due to mechanical strain such as rubbing or repeated bending or expansion/contraction. More preferably, it is 0.1 dl/f or more because it increases the durability of organic solvent resistance and antistatic property.

The above-mentioned intrinsic viscosity is the viscosity of a solution obtained by dissolving the copolymer of the present invention at a concentration of 0.5 f/100 ml in a solvent consisting of 97 ml of dimethylacetamide and 3 vol. of water, calculated using the following formula. be.

Intrinsic viscosity = natural logarithm (solution viscosity/solvent viscosity) 10.5 The copolymer of the present invention is a copolymer with a minute and uniform particle size, and when processed into fibers, paper, etc., the copolymer is uniformly distributed throughout the product. It is a copolymer that coalesces well, imparting durable and excellent antistatic properties, and provides an emulsion with minute and uniform particle size that is useful as a soap-free latex for diagnostic reagents.

EXAMPLES The present invention will be specifically explained below with reference to Examples, but the present invention is of course not limited to the following Examples. It should be noted that all percentages and parts shown in the examples are based on weight unless otherwise specified.

In addition, the particle size and surface electrical resistance of the emulsions in Examples were measured by the following methods.

Particle size: Using a spectrophotometer FPW-4 (manufactured by Hitachi, Ltd.), the white light transmittance of a diluted emulsion solution with a solid content concentration of 0.4% was measured, and the relationship between particle size and transmittance, which was determined separately, is shown. The particle size was determined using the calibration curve. JI under 40% humidity
Surface electrical resistance was measured according to S6911.

Example 1 40 parts of sodium P-styrene sulfonate (abbreviated as 5PSS), 30 parts of styrene (abbreviated as St), and 20 parts of methyl methacrylate (abbreviated as MMA)
0 parts of ion-exchanged water. The polymerization rate was 92%. The intrinsic viscosity of the obtained copolymer was 0. 'idl/
1, and the average particle size of the emulsion was 0.07μ.

The obtained polymerization liquid was diluted with water to give a 0.2% dispersion 1
A woven fabric using highly twisted polyester yarn is mixed into a dispersion liquid at a bath ratio of 1:
After dehydrating, dry at 80°C for 30 minutes. The surface resistivity of the resulting treated cloth was 7.3 x 1
010Ω, and has sufficient antistatic properties.9. (The antistatic effect can be obtained when the surface resistivity is less than 1011Ω.) In addition, the treated fabric was disassembled and the fibers were observed under a microscope.

The copolymer was uniformly attached to the fiber surface.

Examples 2-14. Comparative Examples 1 to 6 Copolymers having the compositions shown in Table 1 were polymerized in the same manner as in Example 1, treated in the same manner as in Example 1, and their surface resistivities were measured. The woven fabric was then disassembled and microscopically observed to see if these copolymers were evenly and evenly adhered to each fiber.

Table 1 Example 15 A copolymer was obtained in the same manner as in Example 1 except that butyl methacrylate was used instead of MMA in Example 1. The polymerization rate was 88%, the particle size of the emulsion was 0.05μ, and the intrinsic viscosity was 0.65 di/l.

When the copolymer was applied to a polyester cloth, the surface resistivity was 7.3×10aΩ, and the copolymer was uniformly coated on each fiber.Comparative Example 7 A copolymer was obtained in the same manner except that stearyl methacrylate was used instead of MMA. The polymerization rate is 6
The emulsion was as low as 3%, and no fine emulsion was obtained.

Example 16 St/5PSS/MMA=85/1.5/1.
A copolymer having a composition of 5 C molar ratio) was obtained in the same manner as in Example 1. The particle size was 0.09μ. This emulsion was diluted to a solid content of 1 g, reacted with human ItG (immunoglobulin G, manufactured by Hoechst) at 37°C for 180 minutes, and the amount of human ItG adsorbed was measured by enzyme immunoassay. St/S P S S
The amount adsorbed was similar to that of the copolymer emulsion. Therefore, latex for diagnostic reagents can be obtained industrially advantageously using a normal polymerization apparatus without using any special polymerization apparatus.

[Brief explanation of the drawing]

FIG. 1 is a triangular coordinate system showing the range of each composition ratio of the copolymer of the present invention. Patent applicant: Toyobo Co., Ltd.

Claims (1)

[Scope of Claims] 3 to 90 molty structural units represented by the following formula CI), 1 to 90 molty structural units represented by the following formula (I[), and 1 to 60 molty structural units represented by the following formula (II) A styrenic copolymer with a molecular weight of 2,000 to 1,000,000. H3 Shiri υ